Choke control



Nov. 7, 1939. THOMPSON I 2,179,141

CHOKE CONTROL Filed April 28, 1939 E l E- lNVENTOR K/AMES D. 7Z/0/v7p5o/v ATTORNEY Patented N... 1, 1939 cnoxa common James D. Thompson, Eureka, Calif. 7 Application Alli] zs. 1939. Serial No. 270,562

This invention relates to an a control for automotive motors.

- Manual choke controls are well known as are their limitations. If forgotten for a few moments matic choke aftertheir purpose is served, they waste fuel.

and flood'the motor.

It is an object of the present invention to com- Thermostatic choke controls have for the most part superseded manual ones, but in turn have disadvantages, particularly in cold weather. They must be set to go clear to the "01! position at about degrees motor temperature or they are wasteful. If the motor is stopped as for a traflic light at about this time, the motor is very diflicult to start. They have other disadvantages that are well known.

Q1: the virtues of the hand operated choke with thermostatic choke and eliminate the disadvantages of both kinds.

It is another object of the present invention to so arrange a choke control that it cannot flood the engine or waste fuel for more than a very short timebefore automatically going 01!.

It is a further object to arrange the control so that it can be put 'partly on or full on, according to the driver's judgment and then easily moved either way, instantly, it the judgment appears by results to need correction.

It izlguther object to so arrange a self-opening chok that the rate of'its opening will vary accor to heat of the motor, of which it is an auxiliary, holding the choke and gradually letting it oil as the motor when starting from cold, and contrariwise permitting closure to "o position almost instantly it wrongly pulled on when the motoris at operating temperature. I

I attain the stated objects bystructure illustrated as a preferred embodiment of the invention in the accompanying drawing, in which:

Fig. I is a sectional elevation of my choke control attached to the instrument board of an automobile; 1

Fig. II is a diagrammatic view of. a part of the motor of an automobile, so placed with respect to the device of Fig. I that it serves to explain the relationship between the motor and the choke control; and

Fig. m is a section on the lines n1 r1r, Fig. I. V

In the drawing, I is a choke control rod of the type familiar to automobile drivers for many years. 2 isthe handle by which it is pulled out from an instrument board- 3 to choke ,the carburetor of the motor, not shown. It is ihtendedto -employ choke control with the well known hutterflv choke concerning which no Thepistonis qllli lled operative to relieve the trapped fluid behind the by-pass A suitable connection marked I a, will work instruction is necesary. from that part of the rod the choke. On the opposite or back side of the instrument board I mount a hydraulic check cylinder 5 that l5 contains a piston 6 which is movable therein. with one-way valves I and the cylinder 5 will be nearly-full of-hy-. draulic fluid. A spring 8 constantly urges the piston t against fluid trappedby' the one-way valves, at the same time urging the rod 'ljto open the choke.

The piston 6 is slidably mounted for relative movement on the rod l within limits fixed by the collar II and the flanged plate ll. V

The mode oi operation of this structure isobvious. When the rod I is pulled-out 'asshownin Fig. I, where it is pulled part way, the choke will be on proportionately to the amount of the pull and will be hydraulically locked in the position in which it is leit, saving for a very small by-pass indicated by the groove in that part of the rod l where it passes through the piston 6, indicated by the numeral l5; hence, assuming that the rod has just been pulled to the'position amount of choke will slowly become less under the influence of pressurejon-the piston t'by the spring I, 'which tends to make the groove l5 valves 1. 7 7 There is another very important feature about this device. Should the rod be inadvertently pulled too i'ar,.which would flood the v motor, it may be instantly pushed back by pressure onthe handle 2, relatively displacing the rod-fl with re-' spect to the piston S, which brings the flanged plate I l' into engagement with the valves I and by-passes the piston 6 completely. It is at once seen that the choke rod I can be moved freely in either direction so that the motor will just start at the present temperature conditions. left there and that as time passes it will automatically come to full "01!" podtion. I K d It will be important, however, in the interests of iucl economy to so supplement the by-pass l5 when the motor warms up that the by-passing is hastened; hence the cylinder 5 is equipped with tube I, which is controlled by the valve ll in turn controlled by-tl ethermostat so positionedthat it will be sensitiveto heat developed in the motor, diagrammatically indicated the numeral 2|, the transmission between the thermostat II and the valve ll being illustrated by the well known sheathed wire 2!;

25 shown, the motor will be partly choked which The valve 11 will be so proportioned as to make the return of the rod I almost instantaneous, when the motor is hot.

The representations as to design are conventional and illustrate mechanical and hydraulic principles rather than the structure as it will be actually constructed and used. For example, there are three stufiing boxes when in practice only one will be absolutely necessary, but the designing engineer will understand all of this without further instruction.

It will be immediately perceived that the old manual choke has been rearranged with other elements that do not in any way prevent hand manipulation as before, but when left and the users attention distracted by driving, it gradually works to oil position automatically in any event and much faster if the engine is well warmed up.

The driver will not in any case be handicapped'in applying any degree of choke he wlshes in starting the engine after a stop have eliminated the greatest fault of the thermostatic choke, which was that if set so that it would be economical after warming up the engine, it tended to go off at so low a temperature that difliculty was experienced if the motor was stopped just at the time the thermostat turned the choke off.

The novel features of this structure that I consider to be new and of my own invention are pointed out in the following'claims.

I claim:

1. In a choke control device for an internal combustion motor, a manually operative choke closing device that is equipped with a spring to restore it to open position when released, a hydraulic check that is operatively set to oppose the spring and means controlled by the temper,- atureof the motor that are efiective to modify the action of the hydraulic check according to motor temperature. v

2. A' manually operable choke control device for a motor that is equipped with a spring positioned to restore a choke to openposition upon release by the user's hand, a hydraulic check connected thereto that is effective to slow the action of the spring, valve means for varying the action of the hydraulic check and thermo-' static means positioned to be sensitive to motor temperature that are effective to control the said valve.

3. In"a choke control, a choke operating rod, a spri choke and a hydraulic check arranged to slow the action of the spring, characterized by means operable by manually pushing the rod towards closed position that are efiective to by-pass the hydraulic check.

4. In a motor choke control of the character described, a manually operable choke control rod, a spring positioned to urge the rod to open theichoke, a hydraulic check that opposes the action of the spring,

to neutral or "ofl position motor heat sensitive and by this means I positioned to urge the rod to openthe a by-pass that permits slow yielding of the hydraulic check and thermostatically controlled means to accelerate the yielding of the hydraulic check that are responsive to temperature conditions 01 the motor.

5. In a'motor choke control, manually operative means for initiating choke conditions, spring means tending to return the choke to inoperative position when -manually released, a hydraulic check arranged to slow the action of the spring, a fixed by-pass for the hydraulic check and a supplementary by-pass having a valve and a thereto.

6. A manually operable spring closable choke control, defined in part as a choke control rod, a spring that urges the rod to open choke position, a hydraulic check that opposes the spring, abypass thatis eflective to cause the check to yield slowly, a thermostat anda thermostaticallycontrolled by-pass device that is responsive to the motor of which the choke control is an auxiliary to further modify the movement of thecheck according to motor tem-. perature.

7. In a choke control apparatus, a choke control rod that is manually movable to apply or release choke, a spring tending to normally return the choke control rod to release position, a hydraulic check connected to the control rod in such manner to effect slow closing, thermostatic means for increasing-the closing rate and means for bypassing the hydraulic check by manually moving the control rod toward release position.

8. In choke control apparatus for a motor engine, a choke applying means, a spring 'means positioned to restore the choke to normal position, a hydraulic check device that is effective to modify the-action of the spring and a thermostatic device which is sensitive to engine temperature that is operatively connected to the hydraulic check to further modify the action of the. spring. Y

9. In a hydraulic check for a choke control, a cylinder, a piston movable in 'saidcylinder, to draw fluid therein, a rod that is manually movable to move the piston one way, valve means in said pistonthat tend to open to fill the cylinder with hydraulic fluid, by-pass means and spring means that tend to empty the cylinder slowly and means operable by the rodto hold the valve means open when manual force is applied to the rod, tending to expelhydraulic fluid therefrom.

10. In a choke control, a choke operating rod, spring means that are normally effective to restore the rod and choke to inoperativeposition, a hydraulic clieck that is arranged to slow the action of the spring, a by-pass for the draulic check, a valve in that by-pass that is mo able to vary the flow capacity of the by-pass and motor heat sensitive thermostat operatively co' acted to said valve.

' JAMES D. THOMPSON.

thermostat connected that it normally resists the spring 

